A prior art hole saw apparatus of the same inventor utilizes a flywheel body to cut holes of up to and above 12″ into I-joist webs while being powered by a low torque power tool such as a hand held power drill. A circumferentially evenly distributed flywheel mass balances out for uneven saw tooth engagement and sudden cutting force spikes. During repeated retraction of the saw blades from the circular cutting groove to clear out the saw dust, the power drill induces kinetic energy into the flywheel body that assists in providing sufficient cutting force on the peripheral saw blades during their alternating cutting action.
The saw blades and arbor in this prior art flywheel holesaw are combined with the flywheel body in well known fashion via machined recesses, holes and contours that are offset from one or the other side of the flywheel body. Due to the high centrifugal forces and potentially strong impacts of the fast moving circumference of the flywheel body, it needs to be fabricated from a light yet strong and impact resistant material such as aluminum alloy that may require CNC machining in its prior art configuration. Unfortunately, CNC machining is cost intensive and consequently limiting commercially viable utilization. Therefore, there exists a need for a configuration of the flywheel body that provides on one hand for a utilization of a high grade aluminum alloy while at the same time keeps fabrication costs to a commercially viable minimum. The present invention addresses this need.
There is a need for cutting large size holes in varying diameters and depth. Having to manufacture and/or purchase a complete flywheel holesaw for each commonly needed diameter and depth needed to be cut is again limiting commercial feasibility. Therefore, there exists a need for a modular flywheel holesaw and system that requires only one part to be exchanged to adapt the modular flywheel holesaw to a broad range of hole diameters and hole depths to be cut. At the same time, all components involved need to be manufactured cost effectively. The present invention addresses also this needs.